Full ball and socket assembly



Feb 1967 R. J. THIERRY ETAL 3,303,742

FULL BALL AND SOCKET ASSEMBLY Filed May 18, 1965 4 Sheets-Sheet lINVENTORS Eu'ber'i J ThiEI Ty 53 BY ZZZ @Wi y;

ATTO-RN EYS Feb. 14, 1967 R. J. THIERRY ETAL FULL BALL AND SOCKETASSEMBLY 4 Sheets-Sheet 2 Filed May 18, 1965 ATTORNEYS j s R O T N E V mFeb. 14, 1967 J. THIERRY ETAL 3,303,742

FULL BALL AND SOCKET ASSEMBLY Filed May 18, 1965 4 Sheets-Sheet 5ATTORNEYS Feh 14, 1967 R. J. THIERRY ETAL 3,303,742

FULL BALL AND SOCKET ASSEMBLY Filed May 18, 1965 4 Sheets-Sheet 4INVENTORS RULE-r1 J-Thia1-1 y 5 Eph En [ll-in TV 11111.

ATTORNEYS 3,305,742 FULL BALL AND SU CKET ASSEMBLY Robert J. Thierry,Aver-iii Park, and Stephen C. Horvath, Troy, N.Y., assignors to theUnited States of America as represented by the Secretary of the ArmyFiied May 18, 1965, Ser. No. 456,870 Claims. (Cl. 89-67) manufacturedgovernmental royalty there- The invention described herein may be andused by or for the Government for purposes without the payment to us ofany This invention relates to a ground mount for muzzleloading guns,such as mortars, and is more specifically directed to an improved balland socket joint for coupling the gun to the mount.

In those mortars which are mounted on a stationary baseplate design-edto lie on the ground, the required traverse of the firing tube inazimuth and elevation is generally provided by a ball and socket jointwhich serves to connect the firing tube to the baseplate. In this typeof joint, the ball is ordinarily attached to or made an integral part ofthe free end of an arm extending rearwardly from the breech end of thefiring tube While the socket is formed into the baseplate for rotatablereception of the ball. Although this design effectively provides themaneuverability required to rapidly adjust the aiming position of thefiring tube in the event of a change in the location of the target, thevarious ball and socket joints heretofore utilized in mortars do notmeet current military requirements.

For one thin, past experience with mortars of all sizes has clearlyshown that the stability of the firing tube and the resulting accuracyof fire can be greatly improved by the utilization of a ball and socketjoint in which the ball is of maximum diameter in order to minimize theshocks imparted to the baseplate by the recoil forces transmittedthrough the firing tube during the discharge of a projectile therefrom.However, up to now, the advantages obtained by an increase in the sizeof the ball have been virtually nullified by the accompanying increasein the length and width of the support arm required to support the ball.Obviously, any increase in the size and weight of the firing tubedetracts from the ease of handling and the mobility which is sonecessary in modern infantry weapons.

Accordingly, it is an object of this invention to provide an improvedball and socket joint for coupling the muzzle-loading firing tube of amortar to a stationary baseplate without the necessity for any supportarm for the ball.

It is a further object of this invention to provide a ball and socketjoint as aforesaid which will permit a significant decrease in thelength and weight of the firing tube and in the size of the baseplate.

Another object of the present invention lies in the provision of a balland socket joint for a mortar wherein the interior of the ball may beutilized to house the firing mechanism.

In addition, since mortars are generally loaded from the muzzle end, anyfailure to fire due to defective ammunition will prevent furtheroperation thereof until the unfired round can be removed from the firingtube. This can be accomplished in a rapid and safe manner by completelyremoving the firing tube from the baseplate and dumping the defectiveround in a protected area away from the mortar emplacement. However,considerable difficulty has been experienced in removing the ball fromthe socket with the required rapidity. For one thing, the need forretaining the ball in the socket against accidental or prematureseparation complicates the assembly and disassembly thereof. Forexample, where the socket is formed in separate halves secured to thebaseplate by suitable locking means accessible from the exterior, thetime required to unfasten and separate the halves is well beyond theacceptable limits which have been established for the safe disposal ofdefective ammunition.

In another attempt to retain the ball in the socket without undueinterference with the ease of assembly and disassembly, the interiorperiphery of the socket is extended above the diametrical axis thereofand diameter of the ball is reduced along the cylindrical sectionencircling the exterior thereof to form a band with a slightly smallertransverse dimension than the distance across the open top of thesocket. Thus, the ball will be retained in the socket in all positionsof rotation except the one in which the diameter of the band coincideswith the distance across the open end of the socket. While suchstructure provides the required rapidity of assembly and disassemblybetween the ball and the socket, the circumferential area occupied bythe band reduces the available bearing surface of the ball to suchextent that the increase in the unit stress on the bearing surface ofthe socket far outweighs the advantages gained by the simplicity of themeans for retaining the ball in the socket. Furthermore, the necessityfor a socket wall surface which extends above the diametrical axisthereof produces an undesirable increase in the overall weight of themortar as well as in the cost of fabricating the joint.

It is, therefore, a further object of this invention to provide a balland socket joint for a mortar wherein the ball is normally retained inthe socket in the manner which does not require that the depth of thesocket exceed the radial dimension thereof.

Still another object of this invention is to provide a ball and socketjoint as aforesaid which is particularly adapted to resist the torqueimparted thereto in the event the mortar utilizes a rifled firing tube.

Finally, it is a general object of this invention to pro vide a ball andsocket structure for a mortar which will enable the firing tube thereofto be rapidly removed from the baseplate with a minimum of manipulationand without the use of tools.

It has been found that the foregoing objects can be achieved by a balland socket joint in which the ball is formed as a hemisphericalcontinuation of the breech end of the firing tube and is rotatablyseated in a mating spheroidal socket formed into the baseplate. Insteadof depending on the curvature of the entire socket wall to retain theball therein, this is accomplished by a pair of blocks verticallymounted at diametrically opposed locations on the top of the socketwalls in position to continue the spherical contour thereof for matingengagement with the similarly contoured peripheral surfaces on a pair ofwing lugs projecting from opposite sides of the firing tube adjacent thebreech end thereof. Since the spherical peripheries of the wing lugs areconcentric with the hemispherical breech end of the firing tube, thelatter can be rotated in the socket to provide azimuth or elevationaladjustment or a combination of both. Such structure provides therequired bearing surface contact between the ball and the socket withoutthe necessity for the additional size and weight which would be createdin the joint if the socket were enlarged to receive the entireperipheral surface of the ball.

Furthermore, the ball and socket joint of this invention is particularlyadapted for the rapid removal of the firing tube from the baseplate.This is accomplished simply by elevating the tube to a vertical positionand then rotating it about the vertical axis thereof in either directionto withdraw the wing lugs out from under the retaining blocks.

Further objects and advantages of the invention will be apparent fromthe following specification andthe accompanying drawings in which:

FIG. 1 is a side elevational view of a typical mortar provided with theball and socket joint of the present invention;

FIG. 2 is an enlarged view of the joint sectioned to reveal the interiorconfigurations of the ball and the socket and broken away in one area toshow the tip of the firing p FIG. 3 is an enlarged top view of thesocket portion of the baseplate with the firing tube removed;

FIG. 4 is a view similar to that of FIG. 3 but with the firing tubeshown in a azimuth position with an elevation of substantially 45";

FIG. 5 is a top view similar to that of FIG. 4 but with the firing tubeshown in the 90 vertical position thereof with the wing lugs rotated outfrom under the retaining blocks;

FIG. 6 is a vertical section taken along line 66 in FIG. 4 to show theengagement between the wing lugs and the retainer blocks;

FIG. 7 is a side View of the breech end of the firing tube; and

FIG. 8 is a rear view of the portion of the firing tube illustrated inFIG. 7.

While the ball and socket joint of the present invention may be utilizedas a coupling between any two members subject to axial loads, it isparticularly effective in a mortar which must be readily disassembledinto separate units each of which can be handled by a single individual.As shown in FIG. 1, a typical mortar of this type consists of abaseplate 12 adapted to lie directly on the ground and provided with acentrally disposed socket 14 for rotatably receiving the correspondinglycontoured breech end of a firing tube 16. Support for the muzzle end offiring tube 16 is preferably provided by a bipod 18 containing anelevating mechanism 21) operable by a' suitable handwheel 22 for rapidadjustment of tube 16 to any desired angle within the maximum andminimum limits of travel.

The breech end of firing tube 16 is formed as a hemispherical section 24which is cylindrically extended forwardly, as indicated at 26 in FIG. 2,to provide a threaded interior 28 for engaging the correspondinglythreaded end 30 of the cylindrical section of tube 16. An annular pocket32 is provided within the interior of section 24 to form a centrallydisposed housing 34 in which a firing pin 36 is threadably secured toprotrude from the forward end thereof.

A generally rectangular wing lug 38 is integrally formed or suitablysecured to the breech end of firing tube 16 at diametrically oppositelocations thereon disposed at the junction of sections 24 and 26. Asbest shown in FIG. 8, the exterior periphery of each wing lug 38 isspherically contoured with a larger radius than the periphery ofhemispherical section 24 but concentric therewith. A clearance angle 40is provided downwardly along the rear face of each wing lug 38 for apurpose to be shown.

While basplate 12 need not be of any particular shape, economy offabrication requires that socket 14 be replaceable therein. Accordingly,as best illustrated in FIG. 2, socket 14 is formed in a circular body 42having a spheroidal underside and removably seated in a correspondingopening 44 centrally disposed in baseplate 12. Socket body 42 isretained against tilting in opening 44 by the circumferential rim of acircular plate 46 secured to the top of baseplate 12 by a plurality ofradially disposed bolts 48. A resilient O-ring 50 is seated in acircumferential groove 52 provided in the exterior periphery of socketbody 42 to prevent dirt entering opening 44.

The upper portion of socket body 42 is recessed to form a spherical zone54 defining a circular wall'56 with a vertically curvilinear face 58surrounding socket 14 but concentrically spaced therefrom to provide acircular track 60 for a purpose to be shown. Fixedly secured to the topof wall 56 at diametrically opposite locations thereon are a pair ofarcuate retainer blocks 62 provided with spherical inner faces 64coextensive with the curvilinear face 58 of wall 56. Although thespherical contours on retainer blocks 62 and on wing lugs 38 areradially equivalent, the peripheral extent of inner face 64 in bothaxial directions is greater than the corresponding dimensions along theexterior periphery of wing lug 38. Midway of blocks 62, a portion oftrack 60 is elevated, as indicated at 66, to extend the sphericalcontour of socket 14 to substantially the same height as the top of wall56 in order to provide additional bearing surface for the hemisphericalbreech end of firing tube 16.

In the event the bore of firing tube 16 is rifled to increase the rangeof the projectiles fired therefrom, the resulting torque loads on tube16 must be nullified or counteracted in order to maintain the requiredstability thereof during firing. This is accomplished by providing aprojecting pin 68 on the breech end of firing tube 16 substantiallymidway of wing lugs 38 thereon and a rectangular slot 70 equal in widthto the diameter of pin 68 intersecting socket 14 diametrically oppositeelevated portion 66 at the rear thereof.

To assemble firing tube 16 to baseplate 12, the breech end of the formeris first vertically lowered into socket 14 with wing lugs 38 angularlypositioned to lie between retainer blocks 62. Then, tube 16 is rotatedabout the vertical axis thereof to bring wing lugs 38 thereon intomating contact with inner faces 64 of retainer blocks 62 and suchrotation is continued until torque pin 68 is aligned for entry intorectangular slot 70. Thereupon, firing tube 16 may be lowered androtated to the desired firing attitude.

Rotation of firing tube 16 in azimuth is limited by the contact of thesides with retaining blocks 62. However, this azimuth movement may beincreased by the removal of the forward inner corner of each block 62 asindicated at 72. Although clearance angles 40 on wing lugs 38 preventinterference with track 60, depression of firing tube 16 in elevation islimited by the contact thereof with the rim of socket 14 along theforward portion thereof. Additional depression of tube 16 may beobtained by elongating the spherical contour of socket 14 in thedirection of slot 70, as best shown at 74 in FIG. 3, to form aspheroidal contour. In order to achieve the benefits of this elongationof socket 14, a corresponding portion of the upper edge of wall 56 isforwardly beveled as best indicated at 76. In addition, track 60 isprovided with shallow arcuate depressions 78 below each retaining block62 to prevent interference with wing lugs 38 during elevation whenfiring tube 16 is adjusted to either limit of its azimuth range.

Thus, when the mortar is fired, the resulting recoil loading isdistributed over the interior of socket 14 and the inner faces 64 ofretaining blocks 62 with a contribution by elevated portion 66 in thelower elevations of tube 16. Any torque loading is counteracted by thecontact of pin 68 on the walls of slot '71 Disassembly is rapidlyeffected by elevating firing tube 16 to the vertical position thereof inwhich torque pin 68 is withdrawn from slot 70 and then rotating tube 16in either direction about the vertical axis thereof until wing lugs 38clear retaining blocks 62. Thereupon, firing tube 16 is free to belifted out of baseplate 12.

Thus, there is here provided a ball and socket joint which isparticularly advantageous for use in mortars. The ability to utilize thebreech end of the firing tube as the ball enables a substantialreduction in the length and weight thereof which benefits the loading ofthe ammunition as well as the transportability of the weapon. Thebearing contact between the wing lugs and the retainer blocks permits asubstantial reduction in the sizes of the ball and the socket withoutany corresponding sacrifice in the ability of the joint to withstand theforces encountered during firing of the mortar and prevent anyinstability of the firing tube which might reduce the accuracy of fire.Furthermore, the ball and socket design described herein is highlydesirable in view of the minimum of manipulation involved in effectingthe complete removal of the firing tube from the baseplate. This featureis particularly important in providing a maximum of safety when clearingthe firing tube of any round which fails to fire. Another desirablefeature of the ball and socket joint is the simplicity and economyinvolved in the fabrication thereof in any quantity due to theconcentricity of the various spherical surfaces utilized therein.

The present invention has been described in detail above for the purposeof illustration only and is not intended to be limited by thisdescription or otherwise except as defined by the scope of the appendedclaims.

We claim:

1. A ball and socket joint for a mortar having a baseplate and a firingtube adapted to be loaded from the muzzle end, comprising ahemispherical section coextensive with the exterior periphery of thefiring tube to form the breech end thereof, a pair of wing lugsprojecting from diametrically opposed locations on the exteriorperiphery of said firing tube breech end, the exterior peripheries ofsaid wing lugs being spherically con-toured in concentric relation tosaid hemispherical breech end of the firing tube, a socket body in thebaseplate having a spherical opening disposed for mating engagement withsaid firing tube breech end, and a pair of retaining blocks secured todiametrically opposed locations on said socket body and havingspherically curved inner faces vertically coextensive with the interiorperiphery of said spherical socket opening for rotatable matingengagement with said exterior peripheries of said wing lugs whereby thefiring tube is r-otatably seated in the baseplate for elevational andazimuth movement and is retained therein until said wing lugs arerotated out of contact with said retaining blocks.

2. The combination defined in claim 1 wherein the interior periphery atthe forward end of said socket opening is intersected by a rectangularslot, and said firing tube breech end includes a projecting pin disposedsubstantially midway of said wing lugs thereon for entry into said slotin said socket opening in order to prevent rotation of the firing tubein response to any torque loads imparted to the firing tube duringfiring operation of the motar.

3. The combination defined in claim 1 wherein said spherical socketopening is forwardly elongated and the forward rim of said socket bodyis correspondingly beve ed to increase the elevational movement of thefiring tube in the downward direction.

4. In a mortar having a baseplate and a cylindrical firing tubeadjustably mounted thereon, a hemispherical section coextensive with theexterior cylindrical periphery of the firing tube to form a closedbreech end, a firing pin threadably secured in said breech end of thefiring tube, a pair of substantially rectangular wing lugs projectingoutwardly from diametrically opposed locations on said firing tubebreech end, said wing lugs each having a spherical exterior peripheryradially greater than said firing tube hemispherical section butconcentric therewith, a socket body releasably secured in the baseplateand having a centrally disposed spherical zonal recess defining acircular wall with a vertically spherical face, said body having aspherical socket concentric with said vertically spherical face butspaced therefrom to define an adjacent circular track, and a pair ofretaining blocks extending upwardly from said socket body atdiametrically opposed locations thereon, said blocks having sphericallycurved inner faces vertically coextensive with said spherical wall facewhereby the combined surfaces thereof provide hearing engagement forsaid wing lugs during the elevation and azimuth movements of the firingtube.

5. The combination defined in claim 4 wherein the rearward portion ofsaid circular track substantially midway of said retaining blocks iselevated to the height of said wall to continue the spherical contour ofsaid socket for increasing the contact area for said hemisphericalbreech end of the firing tube.

References Cited by the Examiner UNITED STATES PATENTS 1,471,063 10/1923Rognlie 89-37 2,194,849 3/1940 Denoix 894O 2,264,791 12/1941 Fries 89373,112,674 12/1963 Jasse 89-4O References Cited by the Applicant UNITEDSTATES PATENTS 2,599,565 6/ 1952 Lontz.

3,003,399 10/1961 Donner.

BENJAMIN A. BORCHELT, Primary Examiner.

SAMUEL FEINBERG, Examiner.

S. C. BENTLEY, Assistant Examiner.

1. A BALL AND SOCKET JOINT FOR A MORTAR HAVING A BASEPLATE AND A FIRINGTUBE ADAPTED TO BE LOADED FROM THE MUZZLE END, COMPRISING AHEMISPHERICAL SECTION COEXTENSIVE WITH THE EXTERIOR PERIPHERY OF THEFIRING TUBE TO FORM THE BREECH END THEREOF, A PAIR OF WING LUGSPROJECTING FROM DIAMETRICALLY OPPOSED LOCATIONS ON THE EXTERIORPERIPHERY OF SAID FIRING TUBE BREECH END, THE EXTERIOR PERIPHERIES OFSAID WING LUGS BEING SPHERICALLY CONTOURED IN CONCENTRIC RELATION TOSAID HEMISPHERICAL BREECH END OF THE FIRING TUBE, A SOCKET BODY IN THEBASEPLATE HAVING A SPHERICAL OPENING DISPOSED FOR MATING ENGAGEMENT WITHSAID FIRING TUBE BREECH END, AND A PAIR OF RETAINING BLOCKS SECURED TODIAMETRICALLY OPPOSED LOCATIONS ON SAID SOCKET BODY AND HAVINGSPHERICALLY CURVED INNER FACES VERTICALLY COEXTENSIVE WITH THE INTERIORPERIPHERY OF SAID SPHERICAL SOCKET OPENING FOR ROTATABLE MATINGENGAGEMENT WITH SAID EXTERIOR PERIPHERIES OF SAID WING LUGS WHEREBY THEFIRING TUBE IS ROTATABLY SEATED IN THE BASEPLATE FOR ELEVATIONAL ANDAZIMUTH MOVEMENT AND IS RETAINED THEREIN UNTIL SAID WING LUGS AREROTATED OUT OF CONTACT WITH SAID RETAINING BLOCKS.